SharkRF OpenSPOT4 Pro

The openSPOT4 is our latest battery powered, portable, standalone digital radio internet gateway (hotspot) designed mainly for amateur radio use. You can talk with others on digital radio networks by using an openSPOT4, Wi-Fi internet access, and your digital transceiver.

Our team has completely redesigned both the hardware and software, with a multicore CPU and a completely new Wi-Fi module, which means both the web interface and update downloads are blazing fast. The built-in battery has a larger capacity, and the device can work much longer than our previous battery-powered models thanks to the new hardware and optimized software.

The openSPOT4 Pro extends the feature set of the openSPOT4 with onboard transcoding hardware:

  • The openSPOT4 Pro has the best voice quality in cross mode operation
  • Supports D-STAR® cross modes: use your D-STAR® transceiver to access DMR, C4FM, NXDN® networks, or your DMR, C4FM, NXDN® transceiver to access D-STAR® networks
  • Supports call audio playback on the web interface
  • Supports 10 configuration profiles

Compatible digital radio protocols and networks

  • DMR (BrandMeister, DMRplus, DMR-MARC, Phoenix, XLX, TGIF and others)
  • D-STAR® (DCS, REF/DPlus, XRF/DExtra, XLX)
  • System Fusion®/C4FM (FCS, YSFReflector, XLX)
  • NXDN® (NXDNReflector)
  • P25 (P25Reflector)
  • APRS® messaging and location data forwarding (APRS-IS)

Supports cross modes* (example: talk with your D-STAR® transceiver on DMR, and with your DMR transceiver on D-STAR® networks).

State of the art hardware and software design

  • The openSPOT4 and the openSPOT4 Pro are the only complete hotspot on the market which is:
    • customly designed as a fully dedicated device for standalone operation (no Raspberry Pi® or anything like that is used or needed)
    • has a built-in battery
    • has built-in transcoding hardware, and supports D-STAR® cross mode operation*
    • using fully embedded software written in pure C, running on a custom-tailored embedded real time operating system. This means no Linux, no bulky Windows software, no failing SD cards – but extreme durability, reliable operation and fast bootup.
  • No desktop PC software or drivers to install
  • Supports fast battery charging with USB charger detection
  • 20mW UHF RF output, see the specifications
  • Extreme fast bootup: under 5 seconds**** from powerup to connected to a server and ready to use
  • Supports scheduling an automatic daily wakeup and powerdown
  • Built-in Wi-Fi access point mode for quick and easy connecting to Wi-Fi networks
  • Multiple Wi-Fi network support with automatic connect and reconnect
  • Fully automatic over the air firmware upgrades for new features
  • Bright multicolor LED with brightness control for easy real time state and battery LED for charge status monitoring

**** Depends on the speed of the Wi-Fi router, Wi-Fi network and internet connection conditions.

Very easy to use

  • Built-in voice announcements
  • BrandMeister Manager and Quick Call on the web interface for DMR TG/reflector linking/unlinking
  • DMR SMS chat
  • DMR ID database lookup
  • Controllable with calls from your radio to preconfigured IDs/callsigns
  • Built-in echo service for testing

Frequently asked questions

What are the openSPOT4 and openSPOT4 Pro good for?

Let’s say you live in Budapest, and talk to your friends on the local DMR repeater HG5RUC, which is linked to talkgroup ID 216 (TG216) on the BrandMeister network.

If you travel around the world, where you can’t reach the repeater HG5RUC directly, you can still talk with your friends by using an openSPOT4 or openSPOT4 Pro and a DMR (or cross mode compatible) transceiver by connecting it to the same network and talkgroup which HG5RUC uses (TG216, BM). If you speak with your transceiver on the openSPOT4 or openSPOT4 Pro’s frequency, it will route your call to TG216, and HG5RUC will transmit your signals all around Budapest, so your friends will be able to hear and talk to you.

If you don’t have local repeater coverage, the openSPOT4 and openSPOT4 Pro can link you to supported digital networks all around the world. You can talk to people living on the other side of the world very easily.

What if I already have local repeater coverage?

If you do have local repeater coverage, you can still make use of an openSPOT4 or openSPOT4 Pro to avoid interrupting local repeater traffic. You can reach any reflector or talkgroup with it, so you don’t have to disconnect the local repeater and disturb other local users.

What makes the openSPOT4 and the openSPOT4 Pro way better than any hotspot currently on the market?

Currently the openSPOT4 and the openSPOT4 Pro are the only hotspots on the market which are customly designed as a dedicated hardware unit for standalone operation. They do not need a computer, a Raspberry Pi®, an Arduino® board, SD card or any other hardware to operate. They don’t need slow desktop PC software or drivers to install. No Linux knowledge is needed at all. They have a built-in battery and the openSPOT4 Pro supports hardware audio transcoding for the best voice quality.

The openSPOT4 and the openSPOT4 Pro were designed by hardware and embedded software professionals, who are also amateur radio enthusiasts. Its PCB, hardware components and case are very high quality, meet industrial standards and were chosen with practicality and durability in mind. We offer 2 year warranty*** with official support in email and on our community forums.

The openSPOT4 and the openSPOT4 Pro are not MMDVM® clones, they have nothing to do with MMDVM® or Pi-Star, and they are not a Raspberry Pi® wired with a bunch of PCBs in a case (or without a case…).

Using the devices are extremely easy. You can change every setting by opening the built-in web interface with a web browser. You can also use the Quick Setup feature to easily connect the openSPOT4 and the openSPOT4 Pro to a digital network like BrandMeister. Opening the web interface is rarely needed, as you can switch talkgroups, reflectors, and even pre-saved configuration profiles by using your transceiver.

Even the first time setup is very easy. If no Wi-Fi networks are configured, then the openSPOT4 and the openSPOT4 Pro appear as a Wi-Fi network access point on your phone/tablet/PC called “openSPOT4 AP”. Connect to this network, and a connection wizard helps you to connect the openSPOT4 and the openSPOT4 Pro to the available Wi-Fi networks.

Is it available as a kit or does it come preassembled?

The openSPOT4 and the openSPOT4 Pro are ready to use products in a box with all the needed accessories like any other product you can buy from the store shelves in your local electronic department store.

What about warranty and support?

We offer 2 year warranty*** with official support in email and on our community forums. We respond to all emails very quickly. There is a detailed user manual available here. We also have a Facebook page, and a Twitter channel with the latest news.

*** The battery and the USB-C charger cable have only one year long warranty period (70% battery end of warranty capacity).

How do you ship the unit?

We ship with FedEx with tracking. Orders of products in stock are shipped with delivery times of usually 2-5 days even to the most remote parts of the world. You’ll receive your order’s tracking number in an automatic email when the courier service picks up the package.

What’s the shipping cost?

You’ll get the exact shipping cost after registering in our shop with the delivery address and do the checkout.

Where can I find the product specifications?

Specifications are available in the user manual.

What happens if I move between multiple Wi-Fi networks?

The openSPOT4 and the openSPOT4 Pro automatically reconnect if the connection is dropped. You can set up multiple Wi-Fi networks to connect to, so it’s very easy to set it up for your home, vehicle, and work Wi-Fi networks. The device will automatically connect if one of the configured Wi-Fi networks become available.

Can two or more openSPOT4 or openSPOT4 Pros linked together?

Two openSPOT4 or openSPOT4 Pros can be linked together directly without any servers or network infrastructure. Interconnecting two digital radio sites can be easily done this way. You can also create your own private radio network by using our open source server application called SharkRF IP Connector Protocol Server. Multiple openSPOTs can connect to this server, it handles all radio modes, even supports cross mode operation. It also has a nice dashboard.

What is cross mode operation?

For example, the openSPOT4 can convert your DMR radio’s transmission to a System Fusion® network, and when someone talks on the System Fusion® network, you’ll be able to hear it on your DMR radio. This cross mode operation is extremely easy to set up. You can find the list of supported cross modes in the user manual here.

Are there any plans for a VHF version?

The openSPOT4 and the openSPOT4 Pro have a built-in antenna for the UHF band. Currently we don’t plan to ship a VHF (or dual band) version of the product.

The web interface has light and dark themes

Are there any plans for a DMR duplex (dual timeslot) version?

Currently we don’t plan to ship a DMR duplex version of the product.

Why doesn’t the openSPOT4 and the openSPOT4 Pro have a display?

You already have a display on your phone/tablet/computer and also probably on your transceiver which all can be used to interact with the openSPOT4 and the openSPOT4 Pro. You can change all settings using the web interface, and also using your transceiver with the help of a unique feature called configuration profiles.

Does cross mode work with D-STAR®?

In case you use the openSPOT4 Pro, then yes! D-STAR® uses an older codec which is incompatible with the newer one used by DMR/System Fusion®/etc., but the openSPOT4 Pro has built-in transcoding hardware, and it supports cross mode operation with D-STAR® radios/networks. The list of openSPOT4 and openSPOT4 Pro cross modes can be found here.

Will there be support for connecting to Ethernet networks?

You can connect the openSPOT4 and the openSPOT4 Pro to an Ethernet network using a Wi-Fi AP/router device.

Which Wi-Fi band is supported?

The openSPOT4 and the openSPOT4 Pro works on 2.4GHz Wi-Fi channels.

Can I use the openSPOT4 and the openSPOT4 continuously plugged into the USB power supply?

Yes! There’s even a setting which you can activate and then the openSPOT4 and the openSPOT4 Pro will turn on if there is external power available, and turn off if the external power supply is disconnected. This is very useful if you want the device to automatically turn on and off if you use it in a vehicle for example.

What’s the difference between the openSPOT4, the openSPOT4 Pro and previous versions?

The openSPOT4 is a whole new device with the latest technology improvements, built-in battery, beeper, Wi-Fi support, USB-C high tolerance power supply with fast charge support, built-in Wi-Fi and UHF antenna, a 0.5ppm TCXO with factory calibration for very low BER. The openSPOT4 Pro extends the feature set of the openSPOT4 with built-in voice transcoding hardware.

Most of the software components were redesigned to make the whole device extreme fast, future-proof, and use very little power. We’ve added new radio modes and network protocols since the openSPOT1. The web interface is redesigned and now use WebSockets technology which means extreme low latency and a whole lot of new realtime features.

Will there be an Android/iPhone app? is available as an application, but it is optional, as the openSPOT4 and the openSPOT4 Pro can be configured using its web interface. You can open it in any supported browser even on your phone.

Can I use multiple openSPOTs on the same network?

Yes! Make sure each device’s name is unique so you’ll be able to open each one’s web interface by their unique device names. You can change the device name at the Network Settings on the web interface.

D-STAR® is a registered trademark of Icom Inc.
System Fusion® is a registered trademark of Yaesu Musen Co., Ltd.
NXDN® is a registered trademark of JVC Kenwood Corp. and Icom Inc.
APRS® is a registered trademark of Bob Bruninga, WB4APR
Raspberry Pi® is a registered trademark of Raspberry Pi Foundation
Arduino® is a registered trademark of Arduino AG
MMDVM® is a registered trademark of Shenzhen HKCNMA Co., Ltd.


Paul L | MØFOX | Chesterfield UK | IO93HE | Icom IC-7800 | Yaesu FT-980 | FT-902DM | WAB SK46

ICOM IC-905 New VHF/UHF/SHF Transceiver – early 2023

New VHF/UHF/SHF Transceiver

New VHF/UHF/SHF Transceiver – early 2023

Icom will announce an exciting industry first at the Tokyo Hamfair which opens on 20th August 2022. Based on its SHF project, the IC-905 VHF/UHF/SHF SDR transceiver will not only cover 144Mhz, 430Mhz, 1200MHz, 2400MHz, 5600MHz but 10 GHz* as well. (*Optional CX-10G transverter required)

Icom will be publishing a video and pre-release document to coincide with the launch of the show which you can view here:

Paul L | MØFOX | Chesterfield UK | IO93HE | Icom IC-7800 | Yaesu FT-980 | FT-902DM | WAB SK46


MFJ-225 HF/VHF Two-Port Graphic Antenna Analyzer

Take RF testing to the next level with the new MFJ-225! All the basic analyzer
functions you`ve come to depend on plus a host of advanced features like builtin
LCD graphics, two-port VNA measurement, PC-Interface using IG-miniVNA
freeware, precise DDS frequency control, self-calibrating . . . easy-to-use!

Two Analyzers in One
Out in the field, MFJ-225 is a compact completely self-contained handheld analyzer. On the bench it becomes a full-fledged two-port (S21) desktop machine when teamed up with your PC. Using powerful IG-miniVNA freeware, you`ll run detailed data analysis and then print out stunning color-graphic plots to document your work!

Seeing is Believing
Get a big picture every time with MFJ-225`s built-in back-lighted 3-inch LCD graphic display. Make fine circuit adjustments using full-screen easy-to-view SWR bar graph, capture vivid swept displays for SWR, impedance, return loss, phase angle, more! Operation is simple, you can adjust the center frequency, tuning step, and sweep width instantly while viewing your plot, literally shaping it before your eyes.

Continuous HF-VHF Coverage
Tunes from 1.5 MHz to 179.9 MHz with rock-solid stability and no gaps. That`s because the MFJ-225`s VFO is a state of the art programmable DDS (direct digital
synthesis) generator with pin-point 1-kHz frequency resolution. DDS control means no mechanical band switches or tuning elements, just a reliable velvet-smooth optical encoder to glide across the spectrum.

Powerful Clean Signal Source
The MFJ-225 DDS stimulus generator also gives you a leveled -5 dBm signal source for driving mixers, low-power amplifiers, filters, networks, diplexers, and antennas on the test range. And, your test signal is always clean, with over -50 dBc of harmonic and spur suppression. That`s better than many precision lab generators costing thousands of dollars! Connect an external step attenuator, and it becomes a highquality signal generator for peaking sensitive receivers and preamplifiers.

Information Powerhouse
The MFJ-225 simultaneously compiles and displays all important parameters you
need on a single screen, giving you a wider range of results at a glance. You`ll work faster and smarter without the inconvenience of scrolling through menus or making tedious conversions to get your data.

What the MFJ-225 Measures:
• SWR (1:1 to 9.9:1)
• Complex Impedance (R+jX)
• Impedance Magnitude (Z)
• Return Loss (RL, 0-30dB)
• Phase (0-180°)
• Capacitance (0-9999pF)
• Inductance (.1uH-80uH)
• Cable Length (0.5-45m)
• Cable Loss (0-30dB)

Two-Port Flexibility
In addition to traditional single-port (S11) reflected-power measurements, MFJ
features an invaluable advantage of making two-port (S21) forward-power measurements, essential for optimizing filters, diplexers,matching networks, etc. It bridges the gap between a simple scalar analyzer and true vector-analysis performance.

Ergonomic Operation
“Advanced features” conjure visions of greater complexity and more buttons to
push . . . not true for MFJ-225! The graphic display is “advanced” because it places more information at your fingertips without needless scrolling and searching. Also, the layout is unique with three large soft-touch selector buttons located on the front panel next to the screen and a large side-mounted frequency control knob conveniently positioned for your right hand. Everything is located where it needs to be for intuitive operating and unobstructed screen view!

Easy To Power
MFJ-225 can be powered by four AAA alkaline batteries or four AAA Ni-MH rechargeable batteries (batteries not incl.). Optional MFJ-1312D, or any external 12 VDC power is required for the built in recharging circuit with charge indicator LED. LED will light while charging and turn off when cycle is completed. On the bench, power it through the USB power port using any USB power source. Optional USB cable,MFJ-5430

In order to maintain out-of-the box accuracy, all analyzers require periodic calibration checks — a potentially time-consuming operation that may require special RF loads and step-by-step procedures. However, the MFJ-225 uses built-in firmware to perform its entire calibration routine in less than a second! Simply initiate the “calibrate” command and you`re done!

MFJ-225 requires 4 NiMh AAA cells or optional power adapter MFJ-1312D, $15.95.
PC interface requires a USB Type-B cable. Analyzer`s OUT port is SO-239. IN port
is SMA-female. 3 3/32W x 6 1/8H x 1 1/2D inches.

Paul L | MØFOX | Chesterfield UK | IO93HE | Icom IC-7800 | Yaesu FT-980 | FT-902DM | WAB SK46

FreeDMR is a DMR Network for Amateur radio users around the world

On the 9 November 2020, the birth of a new way of working with DMR was born.
A network name was devised and was called FreeDMR.
FreeDMR is the freedom for Repeater, Gateway Keepers and some Hotspots to have full control, instead of being told what has to go where.
We look forward to a great and bright future.

FreeDMR is a DMR Network for Amateur radio users around the world.

FreeDMR is currently looking for OpenBridge connections to connect to a rapidly growing system.
Open Source is here! FreeDMR – Open networking – Reaching out to the World.

Some features include:
Client configuration sent via Protocol Options line.
Dial-a-TG. All talk groups shifting via Private Call on Slot 2.
Voice idents. The repeater’s or hotspot call-sign is (spoken) every 15 mins.
Enhanced OpenBridge via Improved bridge protocol.
Loop detection & handling on the FreeDMR Network.
More features to come.

The FreeDMR Server.

The new system is derived from HBlink and is fully-open source and available on GitHUB. The server software allows the implementation of features as we would like to see them, making the software completely customisable to your needs. This also allows the response to issues and bugs more effectively. This system is bridged to other Servers, providing a frontend system with enhanced functionality. It also enabled repeaters to be able to communicate even if a Server upstream is down. An overview of the added functionality is below. Note, all of this functionality is optional and configurable.


FreeDMR UK (The UK Network)

Enhanced Talk Groups (dial-a-tg)

Implementation of an enhanced version of a low level talks group, including all of the voice announcements, timeouts etc. The confusing numbering used for the old reflector system (TG9) is obsolete. Instead, you can simply manual-dial a private-call to any talk group number to have it routed to Talk Group 9 on Time Slot 2 on a FreeDMR repeater. This also works on Hotspots if you decide to use it. There is control of the timer and fallback to the default Talk Group (Reflector) as before. Another abbreviation of a Enhanced Talk Groups or Reflectors as they were known is “Dial-a-TG”.

Single mode.

Only allows a single Talk Group to be routed to a Time Slot on a repeater/hotspot at one time, whilst the Time Slot is active. Even if several static Talk Groups are set up on the slot. As soon as a Talk Group is keyed up, only that single Talk Group is routed to the Time Slot until either the timer expires or another Talk Group is keyed up, which then replaces the first one. This is similar to Hotspot behaviour on other networks. This works even between Dial-a-TG (TalkGroup 9) and other TalkGroups.

Voice idents.

Optionally, (set in Options) a 15 minute voice ident in DMR can be set on Time Slot 2. The repeater’s or hotspot call-sign is (spoken) “sent” via “All Call” for optional voice ident. “This is CALL-SIGN FreeDMR”

Things it doesn’t do.

Currently we have not implemented:

  • Private calls that transit the network (PC on the current repeater still works)


FreeDMR Server Software by Simon Adlem G7RZU.
Dashboard Monitor by Waldek SP2ONG.
Options Calculator by Jim Nessen K6JWN.
Some images and FreeDMR Network logo’s by José Melo.

Paul L | MØFOX | Chesterfield UK | IO93HE | Icom IC-7800 | Yaesu FT-980 | FT-902DM | WAB SK46

Anytone AT-D878UVII Plus Digital Handheld Radio


Anytone AT-D878UV11 PLUS BLUETOOTH Digital DMR Dual-band Handheld Commercial Radio with Roaming and GPS VHF/UHF Dual-band Digital/Analog Part 90 DMR commercial transceiver with 1.77 inch colour TFT display and GPS.

New AT-D878UV11 Plus model includes DMR Roaming, faster processor and larger memory for future enhancements. Ideal for Fire, Search & Rescue, EMS, Police, Sheriff, Forestry and Security operations. Frequency coverage 144-146 / 430-440 MHz.

Includes USB Programming cable.

Roaming : Built-in DMR Repeater Roaming feature
APRS / GPS Capable : DMR-APRS and Analog TX RX APRS Capable (GPS)
VHF/UHF Dual Band : Monitor two bands at the same time (V+V, U+U & V+U)
Digital DMR and Analog: Features both DMR digital and analog modes on any channel.
High Power Output : 6.0W, 4.0W, 2.5W, 1.0W selectable TX power output
2 & 5 Tone Paging Includes built-in : 2 Tone and 5 Tone Paging feature
Programming Cable : Includes USB Programming Cable, free software available for download.
Color TFT Display :1.77 inch color TFT screen for Day or Night operation. User changeable display and font colors.
Roaming : New Built-in Roaming Feature
APRS (GPS): DMR-APRS and Analog APRS Capable (GPS)
Processor :Faster Processor over the D868UV
Additional Memory: Larger Memory for Future Enhancements TFT Display Background Display and Font Colors are User changeable
Digital Monitor :Monitor One or Two Timeslots
Zone Select :Selectable Zones from Keypad
Auto RX Mode Receiver : Auto Selects to incoming Digital or Analog Signal
GPS : Built-in GPS feature
Memory Channels: 4,000 channels
DMR Talk Groups : 10,000
Digital Contacts: 500,000 (complete worldwide database from DMR-MARC)
Power Levels : 4 programmable power levels: 6/4/2.5/1 Watt Transmit Power Levels.
Zones : 250 zones, up to 250 channels per zone.
Display: 1.77 inch color TFT Screen with selectable dual channel or single channel display.
Battery: Operate 35+ hours between charges with the supplied 3100 mAh lithium ion battery in the power saver mode.
Bandwidth : 12.5 / 25.0 kHz Analog, and 12.5 kHz DMR
Import/Export :Enhanced CPS allows direct input and export of channels, digital IDs and talkgroups.
DMR Compatibility: Supports both Tier I and Tier II operation, making it compatible with DMR repeaters that utilize two-slot TDMA technology.
Amateur Radio: Also operational on amateur radio DMR networks and analog frequencies. Software importable worldwide amateur contact database.
Programmable : FCC 47CFR90.203 requires the keypad locked in the shipping configuration. Software keypad unlocking and re-programming are available with the included USB Programming Cable.
Speaker Connection :2-pin style Kenwood/Wouxun type earphone and speaker mic connection for a variety of accessories.
Quiet Tones :CTCSS/DCS tone squelch with split tone and custom tone capability.
Frequency Range : 144-146 / 430-440 MHz RX/TX
Includded Accessories, manual, BT PPT switch, PC cable, battery, charging cradle, carrying strap, antenna, belt clip